Spectroscopic arc chamber



March 22, 1 960 MITTELDORF 2,929,953

SPECTROSCOPIC ARC CHAMBER Filed Sept. 29, 1959 INVENTORS.

DONALD O. LANDON BY ATTORNEY ARTHUR J. MITTELDORF SPECTROSCOPIC ARC CHAMBER Arthur J. Mitteldorf, Scotch Plains, N.J., and Donald Landon, Jackson Heights, N.Y., assignors to Spex Industries, Inc., Scotch Plains, N.J., a corporation of New York Application September 29, 1959, Serial No. 843,258

4 Claims. (Cl. 313'231) Our invention relates to spectroscopic arc chambers and the like and in particular to are chambers used in burning samples in special atmospheres substantially-free from the outside air yet allowing conditions within the chamber to be observed at all times.

One of the objects of our invention is the provision of an arc chamber wherein the position of the arc electrodes may be observed at all times.

Another object of our invention isthe provision of an arc chamber in which the arc gap between the electrodes may be adjusted relative to each other without opening the chamber.

Another object of our invention is the provision of means whereby the arc electrodes in the chamber may be replaced without the necessity of removing and readjusting the chamber itself; thereby maintaining the alignment of the viewing exit with the spectroscope.

Other objects and advantages of our invention will be apparent from the specifications and the drawings in which:

Fig. l is a side elevation of the top portion of the arc chamber.

Fig. 2 is a side elevation of the bottom portion of the arc chamber.

Fig. 3 is a side elevation in partial cross-section of the assembled chamber showing the openings in juxtaposition.

Fig. 4 is a top cross-section of the chamber with the openings in juxtaposition, taken along A-A of Fig. 3.

Fig. 5 is a cross-section similar to Fig. 4, but with the openings out of register as they are located in operating position.

Referring to Fig. 1 of the drawings 6 is the top of the upper portion of the arc chamber, preferably made of metal, and pierced at its center by orifice 7. Top 6 is annularly recessed at 8 to receive and firmly hold an annular downwardly projecting glass skirt 9 which forms the bell of the upper chamber portion. Centrally located on top 6 and firmly attached thereto is a metal cylinder 10 whose central bore 11 is in alignment with orifice 7 for the purpose of receiving electrode 12, said electrode being held in position in the bore 11 by means of tapped orifice 13 and set screw 14. Bell skirt 9 is also provided with a U-shaped opening 15, the purpose of which will later be explained.

Referring now to Fig. 2, 6a is the bottom of the lower chamber portion of the arc chamber, also preferably made of metal and pierced at its central portion by an orifice 7a. Bottom 6a is also annularly recessed at 8a to receive and firmly hold an upwardly projecting glass skirt 9a, however, the diameter of recess 8a and skirt 9a is greater than the diameter of recess 8 and skirt 9 by an amount which will allow skirt 9 to telescope into 9a as shown in Fig. 3.

As in the top section shown in Fig. l, the bottom section is provided with a metal cylinder 10a, central bore 110 in alignment with orifice 7a, tapped orifice 13a and threaded set screw 14a for the purpose of holding electrode 12a within the bore 11a.

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Patented Mar. 22, 1960 Bottom portion 6a is pierced, at any convenient location away from the center, by an inlet pipe 16 to which a hose 17 may be attached to force gases into the chamber during the analysis. Alignment with the spectrograph is made possible by the protuberance 18 which gives a clear optical path into the chamber when the U-shaped opening 15 is in register with the protuberance 13, as shown by reference to Fig. 5; such registration being accomplished by rotation of the upper chamber by means of handle 19 attached to the upper portion of tube 10. Protuberance 18 is also fitted with a transparent window 18a.

At right angles to the protuberance 18 thereis' located a circular orifice 20 which gives free access into the interior of the chamber when said orifice 20 is in registration with the U-shaped opening 15 of the upper chamher, as shown by Fig. 4, and substantially seals said chamber when orifice 20 and opening 15 are out of register. 1 a I Operation The upper and lower chambers are telescoped together as shown by Fig. 3, and tubes 10 and 10a clamped in separate vises 21 and 21a to which electrical energy wires 22 and 22a are attached, such clamps are common in the art and therefore are not fully shown. The lower chamber is now rotated in its vise until the window 18a is aligned with the optical path of the spectrograph and may remain in this position for as long as is necessary.

The upper chamber portion is now raised to any desired degree and rotated until U-haped opening 15 is in register with orifice 20 (shown in Fig. 4) so that the chamber now has an opening into its interior allowing the electrodes 12 and 12a to be adjusted relative to each other and clamped, to prevent further movement, by means of set screws 14 and 14a. The upper chamber portion is now rotated to the position shown in Fig. 5 so that the chamber is now substantially sealed; but by means of protuberance 18 and window 18a an unobstructed view of the chamber interior is presented to the spectrograph lens so that analysis of materials contained within the gas filled enclosure may be made when an electric arc is struck between electrodes 12 and 12a.

As the electrodes are eaten up by the arc the gap between them becomes too great and this may be rectified by lowering the upper chamber thus eliminating the necessity of touching the electrodes themselves. When renewal of the electrodes is necessary, the top chamber portion is again rotated until the orifice 20 and the U-shaped opening 15 are in juxtaposition, whereupon the operator may reach into the chamber and insert new electrodes without the necessity of removing the chamber, and without moving the lower chamber portion from its alignment with the spectrograph.

Minor changes in our invention may be made by those skilled in the art without departing from the scope of our invention in which.

We claim:

1. In a spectroscopic arc chamber of the character described, an annular upper portion comprising a conductive top, a depending skirt, a centrally located cylinder, having an orifice adapted to receive and hold an electrode therein and a substantially U-shaped opening extending upwardly from the bottom of said skirt; an annular lower portion comprising a conductive bottom, an upwardly projecting skirt of greater diameter than said downwardly projecting skirt, a centrally located cylinder, having an orifice adapted to receive and hold an electrode therein, an orifice and a lensed viewing protuberance in said upwardly extending skirt and a non centrally located inlet pipe in said conductive bottomg'whereby said top portion may be partially or wholly telescoped into said bottom zszassa 3 portion and rotated therein to give access into the interior of said arc chamber when said U-shaped opening and the orifice in said upwardly extending skirt are in juxtaposition and substantially close off the chamber to the atmosphere when out of register while presenting an unobstructed view of the interior of the chamber to said viewing protuberance when said U-shaped opening is rotated to register with said protuberance.

2. In a spectroscopic arc chamber of the character described, an annular upper portion comprising a top, a depending transparent skirt attached to said top, a centrally located conductive cylinder in said top having an orifice adapted to receive and hold an electrode therein and a U-shaped opening extending upwardly from the bottom of said skirt; an annular lower portion comprising a bottom, an upwardly extending transparent skirt attached to said bottom, said upwardly extending skirt being of greater diameter than said downwardly extending 4-. a H, A

wardly extending skirt are in juxtaposition and close off the chamber when out of register while presenting an unobstructed view of the interior of said chamber to said viewing protuberance when said upper portion is rotated to register said U-shaped opening with said protuberance.

3. In a spectroscopic arc chamber of the character described in claim 2, and means for clamping said upper and lower electrodes and said upper and lower portions with relation to each other.

4. In a spectroscopic arc chamber of the character described, an upper bell having a top and an annular depending side, a lower bell having a bottom and an annular upwardly extending side, electrodes affixed to the central portions of said upper and lower bells, said upper bell having its side of lesser diameter than the side of said lower bell; a U-shaped opening in said upper bell and an orifice and a viewing protuberance piercing said lower bell: whereby said upper bell may be telescoped and rotated Within the lower bell for the purposes described.

References Cited in the file of this patent UNITED STATES PATENTS Soulary et al. June 2, 1959 

